Abstract: This proposal's primary purpose if to provide the means and structure to achieve the following goals: (1) Immediate Goals: To develop an evidence-based model that covers decision choices for elderly breast cancer patients and to evaluate the impact of longevity, comorbidity, functional status, treatment response, and patient preferences in determining the best possible treatment pathway, and (2) Long Term Goals: To gain the skills and training needed to become a leader in geriatric-oncology health services research and in preference solicitation techniques in the elderly. The candidate will develop the skills needed for advanced cost-effectiveness modeling, health state construction, and preference solicitation techniques through tutorials, workshops, institutional research seminars, interaction with mentors, and research. UCLA, UCSD, and RAND Corporation will provide resources integral to the candidate's development and research plan. Specific Aims: (1) To expand an evidence-based model to cover most of the decision choices for elderly patients with early breast cancer taking into account functional status and other comorbidities. (2) To identify and develop a small number general cancer and breast cancer specific health states comprehendible to an older population to be used for preference solicitation the feasibility of obtaining specific health state preferences from older breast cancer patients (3) identify and modify methods for preference solicitation in an older population, and to perform a pilot study to compare preferences for treatment between younger (<70), and older (>70) patients; and (4) to use the derived aggregate age-specific utility weight to perform refined age-specific cost-effectiveness analysis. Relevance: This analysis will help determine which decisions in the treatment of older breast cancer patients have the greatest uncertainty and would benefit from clinical trials. The experience and data for this study will be used to develop an R01 proposal to undertake a prospective study with the aim of determining how to individualize treatment plans in older breast cancer patients. [unreadable] [unreadable] [unreadable]